You need plugins for Cabri2/Cabri3D to see
files embedded in htmls below, even if you
have those softwares. To download plugins,please
check these: cabri2 , cabri3D ．Once you install the plugins, you can
manuplate figures on the files with mouse
． To move the whole figure, please drag with
Ctrl key down .For reconstraction, please click the red
inverted triangle.At the bottom, there are also original
cabri files which you can directly manipulate
with Cabri/Cabri3D SOFTWARE (not plugins)．

If you can read Japanese , you can get detailed explanations of these
files and mathematical proves from the PDF
section below. There are one-to-one
links to Cabri/Geogebra files. Note that , however, you should use 'back
button' of your browser when you come back
from these links, if you close the brouser,
it also closes original PDFs.